The new building will achieve carbon neutrality on an annual basis through a combination of high-performance building design, directed biogas and on-site fuel cells that annually will generate more electricity than the building and tenant will use..... " First and foremost, we designed a Class A, commercially viable property, then we devised strategies to make it net-zero."

Beth at Inhabitat noted " To create a true net-zero building, one that literally generates as much or more energy than it consumes, is no easy task." She's right- to a point. The real question is, what to they mean by net zero? A common definition is: "Producing as much energy on an annual basis as one consumes on site, usually with renewable energy sources." One usually achieves this by reducing demand for energy and changing the supply to renewable resources. What have they done here?

Demand

The efficiency measures employed included low-e coating on windows (triple pane windows were not cost-effective given the temperate climate and low HVAC loads), underfloor air supply, efficient curtain walls, and efficient lighting. That got the building to a consumption level of 41.5 kiloBtus per square foot. This compares to an ASHRAE standard of 46 kBtu for a good building. Holtzer commented “You can go sub-40 kBtus, but it can get costly and you may end up having to reduce glass and cutting out natural light. We wanted to do this without changing the class-A design.

OK, so there is really nothing special on the demand side, it's just a slightly better than normal modern Class A building, what about the supply side?

Supply

The building uses a TreeHugger favorite, fuel cells from Bloom Energy, to generate the electricity needed to run the building. As Mike described them in a post earlier, Bloom boxes promise lower energy costs and clean power. They run on natural gas, which is cheap and abundant these days thanks to fracking. As Mike notes, that's not greener than green.

If you take the current U.S. grid average, then a Bloom Box running on natural gas would indeed be clean and produce about half the CO2. But compared to cleaner sources like hydro, wind, solar, nuclear, biomass, etc, you'd probably still produce more CO2.

So they are generating electricity from gas, a lot of it; how does that make it zero energy? Hines explains in the press release:

The fuel cells, acquired from Bloom Energy, will generate approximately 5.0 million KWh of electricity annually, which is above what the building will consume. Total on-site energy production will be roughly equivalent to generating the electricity required to power 1,000 San Diego homes. The fuel cells convert methane into electricity in a non-combustion process. Sufficient methane for the system will be acquired from carbon-neutral sources, such as landfills and wastewater plants, and placed into the national natural gas pipeline system.

In Net Zero, you want to generate enough power on site to heat, cool and light your house; it could be a draughty barn, but if you put enough green gizmos on the roof to generate enough green energy to feed it, who cares?

But this building is even sillier than that; they have built a slightly better than standard building that runs on natural gas (because that's what's coming through the pipe) and basically offset this by buying the equivalent amount of so-called renewable methane. The actual building is no more Net-Zero Energy than my big drafty old house; I buy my electricity from Bullfrog Power and can buy my gas from them too. It will cost me a fortune, but hey, look at me, I own an NZEB Class 4 drafty old barn.

Readers will no doubt complain that once again I am letting the perfect be the enemy of the good, that this is a step in the right direction. It is; the building is more efficient than most, and Bloom Boxes may be slightly greener than getting electricity from the typical California energy mix.